Cristiano Ronaldo’s status for Portugal’s World Cup game against the United States on Sunday remains uncertain.

The Real Madrid star is battling a knee injury that forced him to leave Wednesday’s training session early, as he was spotted limping out of practice with an ice pack wrapped around his knee, the Daily Mail reported.

Ronaldo was considered doubtful to play against Germany in the World Cup opener, but he announced that he was “100 percent fit” before the game and played the full 90 minutes of the 4-0 loss.

Ronaldo went through a series of stretches Wednesday before getting his knee wrapped up and leaving practice 30 minutes early. He watched the remainder of it from the sideline.